Hastelloy C-276 is universally resistant to almost all corrosion. Sometimes, this may bring difficulties in etching marks on the alloy surface. Generally, 95 ml hydrochloric acid mixed with 5 gm. of oxalic acid are used as the etchant for Hastelloy C276. The mixed reagent has stronger acidity hence can be used for etching the corrosive-resistant nickel alloy.